The most mobile-centric properties in the world are two you probably wouldn’t immediately expect: Pandora and Twitter.

The two top-30 Internet businesses, one focused on music and the other on small bits of information, have the largest percentage of their audiences using their products on mobile devices, according to analytics firm comScore.

The information comes courtesy of comScore’s Media Metrix Multi-Platform, a brand new measurement tool released today. The product now considers people using mobile apps, tablets, and smartphones, alongside people visiting from the web, to rank companies by their total digital audiences.

In revising its rankings with mobile data, comScore unearthed a few scintillating finds, one of them being that streaming radio service Pandora is by far the most mobile-centric service on comScore’s list of top 30 propeties.

In September, Pandora’s total digital population was 59.8 million people, good enough for a twenty-third place finish on comScore’s top audience list. More interesting, however, is that the Internet radio business is more of a mobile radio company. Pandora had 48.6 mobile users and 22.6 million desktop users in September, making its mobile audience more than double its web audience.

“The most mobile-centric property in the ranking, Pandora, had an incremental reach of 164 percent and captured the #23 ranking, a full 38 positions higher than in the standard Media Metrix ranking,” comScore said of its tweaked top 30 list, included below.

Twitter is also no slouch in the mobile department. The information network was second only to Pandora with its incremental mobile audience coming in at 54 percent. Twitter, which holds the 26 position on comScore’s audience ranking chart, had a total digital audience of 56.7 million people in September. Desktop users numbered at 36.8 million while mobile users tailed 30.6 million for the month.

The data is telling for a number of reasons, but primarily because it shows that Pandora and Twitter, more so than Google and Facebook, are in the best positions to capture attention amid a massive population shift from web to mobile. It may be a bit of a coincidence, but Pandora shares closed up 7.46 percent for the day even while the company is practically begging Congress members for lower music royalties to save its business.